U.S. teenagers from coast to coast on Wednesday will join students from the Florida high school where a gunman killed 17 people last month in a national class walkout they hope will press policy makers to act on tighter gun control.

The #ENOUGH National School Walkout, scheduled to begin at 10 a.m. local time across the country, will last 17 minutes, commemorating each of the students and staff killed at Marjory Stoneman Douglas High School in Parkland on Feb. 14.

The walkout is part of a burgeoning, grass-roots movement that emerged immediately after the Feb. 14 Parkland attack. Led by student-survivors, activists have lobbied state and federal lawmakers, and even met with President Donald Trump, to call for new restrictions on gun ownership, a right protected by the Second Amendment of the U.S. Constitution.

"It's really amazing how much awareness we've brought to this issue and so many people are willing to participate," said Stoneman Douglas senior Ashley Schulman on Tuesday in a phone interview.

Students from more than 2,800 schools and groups will participate, many with the backing of their school districts, according to the walkout's organizers, who also coordinated the Women's March protests staged nationwide over the past two years.

Support has also come from the American Civil Liberties Union and Viacom Inc <VIAB.O>, which said all seven of its networks, including MTV, would suspend programming at 10 a.m. in each U.S. time zone for the 17 minutes.

The protest will take place a day after Florida prosecutors said they would seek the death penalty for Nikolas Cruz, who has been charged with 17 counts of premeditated murder and 17 counts of attempted murder at Parkland's Marjory Stoneman Douglas High School.

Robert Runcie, the Broward County school superintendent, said the district, which includes Stoneman Douglas, would respect the free speech rights of students and allow them to participate in the demonstration.

But a few school districts around the country have warned against protests during school hours.

Administrators in Sayreville, New Jersey told students that anyone who walked out of class would face punishment, according to myCentralJersey.com. Board of Education President Kevin Ciak said failure to follow the rules would result in suspensions, the news site reported. The district did not immediately respond to a request for comment.

The New York City Department of Education said it would allow students to participate if they submitted a signed permission slip from their parents. It would consider the walkout an excused absence.

In Newtown, Pennsylvania, Council Rock School District will designate an area inside schools where students could gather in a "non-political fashion" to remember the shooting victims. Officials will block all entrance and exit points for the duration of the protest to prevent any walkout.

Robert Fraser, the Council Rock superintendent, sent a warning to parents that any student who walks out of school will face discipline.

More than 40 of U.S. colleges and universities, including Yale, Brown and the Massachusetts Institute of Technology, have said their admissions offices would not penalize any applicants who are disciplined for protesting.

"I, for one, will be cheering these students on from New Haven," wrote Hannah Mendlowitz, an admissions and recruitment official at Yale University, in a blog post in February.

(Reporting by Gina Cherelus in New York; Editing by Frank McGurty and Lisa Shumaker)